DirecTV, which is owned by AT&T, is coordinating with Intelsat on a plan to move Spaceway-1 into a new orbit. DirecTV already disabled the satellite's primary function, which is to provide backup Ka-band capacity in Alaska. The satellite can operate on power reserves from its solar panels, but that won't be possible during the coming eclipse season, DirecTV explained in its FCC filing:

In December, Spaceway-1 suffered a major anomaly that resulted in significant and irreversible thermal damage to its batteries. Boeing, the spacecraft manufacturer, concluded based on all available data that the batteries' cells cannot be guaranteed to withstand the pressures needed to support safe operation of the spacecraft in eclipse operations; rather, there is a significant risk that these battery cells could burst. As payload operations have been terminated, the spacecraft has had sufficient power margin to avoid use of the batteries during sunlight operations. However, use of the batteries during eclipse is unavoidable and there is no ability to isolate damaged battery cells. The risk of a catastrophic battery failure makes it urgent that Spaceway-1 be fully de-orbited and decommissioned prior to the February 25th start of eclipse season.

Not enough time to deplete fuel

Under the standard process for taking satellites out of their normal orbits, "Spaceway-1 would complete its end-of-life maneuvers and then discharge all remaining bipropellant prior to decommissioning the spacecraft," DirecTV wrote.

But because of the explosion risk, there isn't enough time to fully deplete the bipropellant. That's why DirecTV asked for a waiver from the rules.

"Waiver is appropriate in this case because grant would not undermine the purpose of the rule, which is to reduce the risk of accidental explosion," DirecTV wrote. The waiver "will reduce the potential for harm to other geostationary satellite operators," DirecTV said.

DirecTV said it intends to discharge as much fuel as possible before completing the move but that "the priority remains the complete decommissioning of the satellite prior to commencement of the spring eclipse season to limit the risk of an accidental explosion." In the time available, DirecTV said "it will be able to deplete only a nominal portion of the approximately 73kg of bipropellant remaining onboard Spaceway-1." Fully depleting the bipropellant would take two or three months.

"Delayed de-orbit maneuvers or prolonged propellant depletion strategies are not possible given the heightened likelihood of catastrophic failure of the Spaceway-1 satellite should the damaged battery be recharged," the filing said.

DirecTV and Intelsat "are exploring feasible alternatives" for satellite-tracking ground stations "that can maintain ground visibility as the satellite transits from its current orbital position."

"In the absence of additional ground station solutions, Spaceway-1 will first need to increase its eastward drift before turning around and completing a near-continuous burn until it reaches its disposal orbit," DirecTV said.

New orbit 300km above other satellites

DirecTV described its plan as "de-orbiting" and moving the satellite into a "disposal orbit," which would suggest bringing it closer to Earth and letting it burn up in the atmosphere. But the filing also says the new orbit will be "300km above the geostationary arc," which would make it a graveyard orbit. Assuming that's the case, Spaceway-1 would remain indefinitely in an orbit that's well above other geostationary satellites. We've asked AT&T for clarification on this point.

DirecTV asked for a 30-day waiver "beginning no later than January 20, 2020," so it may have already received permission and begun the operation, which is expected to take 21 days. We contacted DirecTV owner AT&T and the FCC about the status of the waiver request this morning and will update this article if we get any response.

DirecTV said that no customers were affected by the satellite problem, since it was just providing backup capacity. DirecTV said it "is currently exploring plans to relocate on-orbit assets to replace the backup capacity lost by the decommissioning of Spaceway-1."

260 Reader Comments

I'm really surprised that they don't have a way to prevent the batteries from charging or some form of battery disconnect system on these satellites. That seems pretty basic, IMO, but then again I'm not a rocket scientist...

I'm really surprised that they don't have a way to prevent the batteries from charging or some form of battery disconnect system on these satellites. That seems pretty basic, IMO, but then again I'm not a rocket scientist...

Well, it would require an EVA to have someone replace the batteries, so we’d need a...

I'm really surprised that they don't have a way to prevent the batteries from charging or some form of battery disconnect system on these satellites. That seems pretty basic, IMO, but then again I'm not a rocket scientist...

Well, it would require an EVA to have someone replace the batteries, so we’d need a...

Is the purpose of "fully depleting the bipropellant " to avoid an explosion upon reentry? I'm unclear as to the reasons for this requirement. Seems like it would all burn up anyway in the upper atmosphere.

Just to add a bit of perspective, this satellite was launched in 2005 and had a rated service life of 12 years. For the last few years it's only been operating as a "backup" satellite, mostly for Alaska. The sat was operating in the "103 West" part of the sky, about 103 degrees west of the Prime Meridian. For HDTV channels from DTV you need some reception for sats at 103 and 99, and legacy SDTV is usually coming from satellites at 101 between them. There are 3 other DTV sats in the same "103 degrees West" part of the sky that have been providing the main broadcasting capability. So losing this satellite probably won't mean anything for current DTV viewers.

They don't have time to vent enough propellant, but can't they burn off the extra much more quickly? For example, instead of going to a graveyard orbit at +300 km, can't they go to one much higher? Or go to a higher orbit first, then come back down, if they really need to be at +300?

Just to add a bit of perspective, this satellite was launched in 2005 and had a rated service life of 12 years. For the last few years it's only been operating as a "backup" satellite, mostly for Alaska. The sat was operating in the "103 West" part of the sky, about 103 degrees west of the Prime Meridian. For HDTV channels from DTV you need some reception for sats at 103 and 99, and legacy SDTV is usually coming from satellites at 101 between them. There are 3 other DTV sats in the same "103 degrees West" part of the sky that have been providing the main broadcasting capability. So losing this satellite probably won't mean anything for current DTV viewers.

Unless it goes supernova and wipes out other satellites or satellites of other services.

I'm really surprised that they don't have a way to prevent the batteries from charging or some form of battery disconnect system on these satellites. That seems pretty basic, IMO, but then again I'm not a rocket scientist...

When have we ever planned for the decommissioning or end of life of anything, mush less the unscheduled end of life.

I'm really surprised that they don't have a way to prevent the batteries from charging or some form of battery disconnect system on these satellites. That seems pretty basic, IMO, but then again I'm not a rocket scientist...

When have we ever planned for the decommissioning or end of life of anything, mush less the unscheduled end of life.

Well, how about "whenever we plan a satellite project"? Decommissioning and/or de-orbiting is a requirement for approval, not to mention a prudent plan.

Obviously this is not normally how things are done. I couldn't get a feel from the article though whether this anomaly is highly unusual/rare, something almost to be expected given how difficult space stuff is, or somewhere in the middle.

Which follows on to query whether the reference to it being a Boeing satellite (in the headline I saw, but not in the article#) is significant or not? It doesn't sound like a complete failure given the plan to move it out of the geostationary orbit height. Is it another embarrassment to add to Boeing's recent woes, or par for the course for end of life satellites?

# edit: I meant that it's a Boeing satellite is not expanded on in the article.

I'm really surprised that they don't have a way to prevent the batteries from charging or some form of battery disconnect system on these satellites. That seems pretty basic, IMO, but then again I'm not a rocket scientist...

Satellites in geosynchronous orbit go through an annual eclipse season when the Earth passes between the Sun and the satellite. Currently, the satellite is drawing power directly from the solar arrays and is configured to avoid charging the battery.

But when the eclipse comes, they'll have to discharge the battery to keep the satellite powered and under control. Charging or discharging the damaged battery risks causing a thermal runaway and an energetic breakup.

That's why they want to get it up into the graveyard orbit before the eclipse, so if it explodes, it does so in a orbit where the debris are very unlikely to disrupt the operation of active satellites.

I'm really surprised that they don't have a way to prevent the batteries from charging or some form of battery disconnect system on these satellites. That seems pretty basic, IMO, but then again I'm not a rocket scientist...

Well, it would require an EVA to have someone replace the batteries, so we’d need a...

I'm really surprised that they don't have a way to prevent the batteries from charging or some form of battery disconnect system on these satellites. That seems pretty basic, IMO, but then again I'm not a rocket scientist...

From another article, they have disconnected the batteries. The issue (I believe) is that it is an all-or-nothing disconnect. From this article it says that the cannot isolate the problem cells. This implies that they can only disconnect all the batteries and not just the bad cells.

Is the purpose of "fully depleting the bipropellant " to avoid an explosion upon reentry? I'm unclear as to the reasons for this requirement. Seems like it would all burn up anyway in the upper atmosphere.

There is no plan to have it reenter the atmosphere, under any scenario. It's far too high for that, and doesn't have nearly enough ∆V to get it back down to where it could reenter. The plan is to actually raise the orbit several hundred kilometers where it theoretically won't damage anyone else when/if it does explode. Dispensing with the propellent is another step which is taken to minimize the risk to any other equipment. Many such spacecraft have to keep their propellent from freezing or the like with heaters. Having propellent freeze and thaw, or even just holding it under pressure is asking for leaks or other kinds of trouble. Much easier and lower risk to use all of the remaining propellent to get it into as high an orbit as possible, where it poses the least risk to anyone.

If I have learned anything from watching movies taking place in space and reading the Expanse series...

Having the satellite stay in a higher orbit is better than letting it burn in our atmosphere. Maybe in 30 or 40 years, space flight will be more common, and a pilot or engineer will be low on biopropellant and their ship will eventually crash into the earth, killing thousands. They do a quick search of decommissioned satellites that make up the junk ring around Earth and find this one, with just enough propellant to get their ship out of a failing orbit. A tense space walk and retrieval later, and lives are saved.

If I have learned anything from watching movies taking place in space and reading the Expanse series...

Having the satellite stay in a higher orbit is better than letting it burn in our atmosphere. Maybe in 30 or 40 years, space flight will be more common, and a pilot or engineer will be low on biopropellant and their ship will eventually crash into the earth, killing thousands. They do a quick search of decommissioned satellites that make up the junk ring around Earth and find this one, with just enough propellant to get their ship out of a failing orbit. A tense space walk and retrieval later, and lives are saved.

Unfortunately of course, by then the bird will be infested with zombies.

Meh, I'm going to give Boeing a pass on this one. A quick google search indicates that the design life of these birds are 15 years. According to the article this Boeing 702HP is already 15 years old.

Granted one could argue that it died just days after the warranty expired like half my electronics, but that wouldn't really be fair to Boeing in this case.

It is not uncommon for either the warranty period to be selected by when components are expected to start failing, or parts be chosen by when the overall product warranty will be set

So you might as well expect that the warranty is statistically all you should expect an item to work for without maintenance when purchasing, and maybe you will get lucky and your components will beat the average.

Is the purpose of "fully depleting the bipropellant " to avoid an explosion upon reentry? I'm unclear as to the reasons for this requirement. Seems like it would all burn up anyway in the upper atmosphere.

It's to minimize the size of the boom and the resulting dispersal of debris, whether the satellite makes it to the graveyard orbit or not. Because this is an end-of-life maneuver, it's not unusual for a satellite to fail to boost itself into the graveyard orbit. Propellant passivization is mostly a backup measure to minimize the potential consequences of a dead satellite stuck in GEO.

There's never been a spacecraft that has attempted reentry from GEO. It's a massive de-orbit burn that's difficult to justify from a high-energy orbit. Maybe Starship will be the first to deorbit from GTO, but even that's not quite the same as deorbiting from GEO.

Meh, I'm going to give Boeing a pass on this one. A quick google search indicates that the design life of these birds are 15 years. According to the article this Boeing 702HP is already 15 years old.

Granted one could argue that it died just days after the warranty expired like half my electronics, but that wouldn't really be fair to Boeing in this case.

It is not uncommon for either the warranty period to be selected by when components are expected to start failing, or parts be chosen by when the overall product warranty will be set

So you might as well expect that the warranty is statistically all you should expect an item to work for without maintenance when purchasing, and maybe you will get lucky and your components will beat the average.

Is the purpose of "fully depleting the bipropellant " to avoid an explosion upon reentry? I'm unclear as to the reasons for this requirement. Seems like it would all burn up anyway in the upper atmosphere.

It's to minimize the size of the boom and the resulting dispersal of debris, whether the satellite makes it to the graveyard orbit or not. Because this is an end-of-life maneuver, it's not unusual for a satellite to fail to boost itself into the graveyard orbit. Propellant passivization is mostly a backup measure to minimize the potential consequences of a dead satellite stuck in GEO.

There's never been a spacecraft that has attempted reentry from GEO. It's a massive de-orbit burn that's difficult to justify from a high-energy orbit. Maybe Starship will be the first to deorbit from GTO, but even that's not quite the same as deorbiting from GEO.

Excuse my ignorance, but I tought that anything below GEO would eventually fall back down to Earth. Why is so much delta-V required to make it come down? Wouldn't a gentle nudge be enough?

I'm really surprised that they don't have a way to prevent the batteries from charging or some form of battery disconnect system on these satellites. That seems pretty basic, IMO, but then again I'm not a rocket scientist...

-snip-That's why they want to get it up into the graveyard orbit before the eclipse, so if it explodes, it does so in a orbit where the debris are very unlikely to disrupt the operation of active satellites.

Out of curiosity, if it explodes, are they just hoping that a large chunk doesn't get displaced right back downward into lower orbits? Or can they put it at an attitude where it most assuredly will laterally eject detritus?

If I have learned anything from watching movies taking place in space and reading the Expanse series...

Having the satellite stay in a higher orbit is better than letting it burn in our atmosphere. Maybe in 30 or 40 years, space flight will be more common, and a pilot or engineer will be low on biopropellant and their ship will eventually crash into the earth, killing thousands. They do a quick search of decommissioned satellites that make up the junk ring around Earth and find this one, with just enough propellant to get their ship out of a failing orbit. A tense space walk and retrieval later, and lives are saved.

I think the octane level on that gas will be too low by then, or some other analogous situation. But I could see this as an episode of MacGyver.

There's never been a spacecraft that has attempted reentry from GEO. It's a massive de-orbit burn that's difficult to justify from a high-energy orbit. Maybe Starship will be the first to deorbit from GTO, but even that's not quite the same as deorbiting from GEO.

Upper stages that deliver satellites to GTO eventually do decay and re-enter, as their periapsis is low enough to experience drag.

For Geostationary satellites, they are put into "super-sync", graveyard orbits. This is "de-orbiting" them. It would take way too much fuel to burn them up in the atmosphere.

When decommissioning, the satellite operators try and get rid of any stored sources of energy. Batteries, propellant, etc. Once the satellite is no longer in active control, you can't keep the tanks away from the sun, etc. And then, explosions.

In general, most satellites won't let you fully disconnect all the batteries (just some), so an accident doesn't happen and you power off the satellite (since you can't power it back on at that point).